Question

I am trying to get started with Castle.Windsor and following a comment I made on the samples currently available for newbies (http://stw.castleproject.org/Windsor.Silvertlight_Sample_App_Customer_contact_manager.ashx?Discuss=1), I thought I’d take the bull by the horns and update the example provided here http://dotnetslackers.com/articles/designpatterns/InversionOfControlAndDependencyInjectionWithCastleWindsorContainerPart1.aspx.

This is a simple and fairly straightforward console application making use of Castle Windsor, albeit an outdated version. My Main method in Program.cs is as follows:

public static void Main()
    {
        IWindsorContainer container = new WindsorContainer();

        container.Install(FromAssembly.This());
        var retriever = container.Resolve<IHtmlTitleRetriever>();

        Console.WriteLine(retriever.GetTitle(new Uri(ConfigurationManager.AppSettings["fileUri"])));

        Console.Read();

        container.Dispose();
    }

and the Service and Components, which are all in the same file i.e. Program.cs are thus:

public interface IHtmlTitleRetriever
{
    string GetTitle(Uri file);

}

public interface IFileDownloader
{
    string Download(Uri file);
}

public interface ITitleScraper
{
    string Scrape(string fileContents);
}

public class HtmlTitleRetriever: IHtmlTitleRetriever
{
    private readonly IFileDownloader _downloader;
    private readonly ITitleScraper _scraper;

    public HtmlTitleRetriever(IFileDownloader dowloader, ITitleScraper scraper)
    {
        _downloader = dowloader;
        _scraper = scraper;
    }

    public string GetTitle(Uri file)
    {
        string fileContents = _downloader.Download(file);
        return _scraper.Scrape(fileContents);
    }
}



public class HttpFileDownloader : IFileDownloader
{
    public string Download(Uri file)
    {
        return new WebClient().DownloadString(file);
    }
}

public class StringParsingTitleScraper : ITitleScraper
{
    public string Scrape(string fileContents)
    {
        string title = string.Empty;
        int openingTagIndex = fileContents.IndexOf("<title>");
        int closingTagIndex = fileContents.IndexOf("</title>");

        if(openingTagIndex != -1 && closingTagIndex != -1)
            title = fileContents.Substring(openingTagIndex, closingTagIndex - openingTagIndex).Substring(7);

        return title;
    }
}

It is pretty much a straight copy of what Simone Busoli has from his example. The code compiles fine but I get the following error when I run the application:

No component for supporting the service WindsorSample.IHtmlTitleRetriever was found

I understand what that means but I don’t know what I’m doing wrong that the components are not getting loaded into the container. I’m using Castle.Windsor 2.5.2 and .NET 4.0.

Looking forward to the answers,

David

Answer 1

Following Krzysztof’s advice, here is how to get my simple example going:

 public static void Main()
    {
        var container = new WindsorContainer();

       // container.Install(FromAssembly.This());
        container.Register(
            Component.For( typeof( IHtmlTitleRetriever ) ).ImplementedBy( typeof(HtmlTitleRetriever) ) ,
            Component.For( typeof( IFileDownloader ) ).ImplementedBy( typeof( HttpFileDownloader ) ),
            Component.For( typeof( ITitleScraper ) ).ImplementedBy( typeof( StringParsingTitleScraper ) )
         );
        var retriever = container.Resolve<IHtmlTitleRetriever>();

        Console.WriteLine(retriever.GetTitle(new Uri(ConfigurationManager.AppSettings["fileUri"])));

        Console.Read();

        container.Dispose();
    }

That will work.

---

Krzysztof, we also tried this

 container.Register(
            AllTypes.FromThisAssembly().Pick().If(Component.IsCastleComponent)
        );

and adorned all the classes appropriately but I still got the same error as before. Can you shed some light on this please?